Give in! 你认了吧.
Admit it! Confess! 你承认吧. 招认吧.
Come clean! 你快招!
Spill your guts! 讲实话!
Give me the whole story. 把来龙去脉说给我听. Give me all the details. 你一五一十讲个清楚.
You've got to reveal it. 你非说不可. If the soft approach doesn't get anywhere then beat it out of him. 软的不行就来硬的, 不怕他不招.